They allege that the company's drilling polluted their water with chemicals,metals and methane, the main constituent of natural gas, causing explosions as well as gastrointestinal and neurological illness.

VOA: standard.2010.01.02

Methane, there are certainly some solid bonds there, but breaking those to form CO2 and water, well it's worth it, right, energetically.

酒精中的确含有很强的化学键，但是打断这些化学键然后生成二氧化碳和水，从能量上来看是值得的。

麻省理工公开课 - 热力学与动力学课程节选

You burn methane, and it combines with oxygen to form water, to form CO2.

燃烧酒精，酒精分子和氧气结合形成水和二氧化碳。

麻省理工公开课 - 热力学与动力学课程节选

In January,a team of NASA and university scientists announced that they had found methane gas on Mars.

VOA: special.2009.12.30

So this should immediately look like a problem because we know, in fact, that methane is tetravalent, and this is telling us it's only divalent.

显然这看起来是一个问题,因为我们知道实际上，甲烷是四价的，而这告诉我们它仅仅是二价的。

麻省理工公开课 - 化学原理课程节选

The orbiter could finally provide evidence about how methane on Mars is created and destroyed.

VOA: special.2009.12.30

Let's go back to methane and see what happens there.

让我们回到甲烷，看看发生了什么。

麻省理工公开课 - 固态化学导论课程节选

This suggests processes that both supply and remove methane from the atmosphere in certain places.

VOA: special.2009.12.30

So, using our simple valence bond theory, what we would expect is that we want to pair up any unpaired electrons in methane with unpaired electrons from hydrogen and form bonds.

利用简单的价电子成键理论，我们预计,要把所有甲烷中没有配对的电子,和氢原子中没有配对的电子配对来形成键。

麻省理工公开课 - 化学原理课程节选

For example,animal waste and cattle digestive systems release methane gas.

VOA: special.2010.01.05

And I picked looking at methane so we could see if there are other factors that we're not considering, that we need to maybe tweak our model a little bit, and I think we'll find that we do if we take a look at a polyatomic molecule, methane, CH4 so c h 4.

我选择甲烷这个例子，我们可以看到,如果有一些我们没有考虑到的因素，我们需要修改一下我们的模型，我们看一看,甲烷CH4这个多原子分子，就会知道这一点，甲烷。

麻省理工公开课 - 化学原理课程节选

Manure from about 1,000 cows goes in one end and then, controlled decomposition yields methane gas at the other.

VOA: standard.2010.02.23

And so, methane is nonpolar.

甲烷没有极性。

麻省理工公开课 - 固态化学导论课程节选

But cars and trucks that run on methane are still a novelty in the U.S.

VOA: standard.2010.02.23

"When the gas comes off the digester, it has not only methane in it it also has carbon dioxide And it has a trace of hydrogen sulfide."

VOA: standard.2010.02.23

Bigger livestock herds are putting greater pressure on land resources and disrupting some ecosystems and the animals generate significant amounts of water and air pollution, including methane, a climate-changing greenhouse gas.

VOA: standard.2010.02.22